Internal & External Protection

Internal Protection

Ductile Iron Pipes are lined internally as standard with cement mortar which is centrifugally applied in accordance to ISO4179 and BS EN 545. The mortar lining has a smooth surface in contact with the water, enhancing flow and reducing head losses.

As a corrosion protection, cement mortar lining is an added advantage to Ductile Iron
Pipes. The lining provides a physical as well as a chemical barrier to corrosion of the
iron wall. It eliminates red rusty water and tuberculation.

High alumina cement lining is available for aggressive sewer applications.

Ductile Iron Pipes may on request, be supplied with the following liners:

Epoxy lining

Ceramic Epoxy lining

External Protection

Ductile Iron Pipes are coated externally as standard with a metallic zinc (not less than 130g/m2) and bitumen in accordance with ISO8179 and BS EN545.

With time the zinc coating transforms into a dense impermeable protective barrier that has the ability to restore the continuity of the protective layer through the migration of zinc irons in areas where local damage may exist. The bitumen coating provides both protection against cathodic corrosion and a suitable environment for the zinc coating to transform into an impermeable coating.

Situations where the zinc based coating can not provide a long-term protection for example acidic soils or soils contaminated by certain wastes, organic or industrial effluent the special coatings should be considered.

Ductile Iron Pipes may, on request, be supplied with the following external coatings: